I ask because I'm interest in learning a bit of scripting.
There's a whole forum topic on the subject, I suggest starting with the oldest ones first and reading them in chronological order to understand the story of why it was created and what it was designed to do:
https://sindome.org/bgbb/development-discussion/script-development/
If you're asking about the programming language which the MOO is programmed in and the game content is programmed in, it's a language called MOO. The MOO itself was originally written in either C or C++, I forget which, and the MOO program implements an interpeter for the "internal" MOO language, which is what basically all the game programming is written in. This is regarded as a scripting language since it's interpreted, and I mention all of this just in case this was what you were asking about, as opposed to the BabbleOn feature, which isn't what runs the game.
The most up to date MOO programming specification, relevant to the ToastStunt version of the MOO engine we're running on, is here:
https://github.com/sevenecks/lambda-moo-programming